Children coughing up sputum with blood, clinically possible causes are localized rupture of nasal capillaries, acute bronchitis, mycoplasma pneumonia and so on. 1. Localized rupture of nasal capillaries: If the air in the environment is dry or the child himself suffers from abnormal secretion of nasal glands, may cause the nasal cavity is dry and make the mucous membrane of the nasal cavity rupture bleeding, when the blood reflux to the pharynx will lead to coughing up sputum with blood. 2. Acute bronchitis: common dust, irritating gases and other environmental irritants and other factors, may induce acute bronchitis, when the child coughs will lead to local respiratory mucosal damage and cough up sputum with blood. 3. Mycoplasma pneumonia: this condition usually occurs in children with low resistance, which may be infected in public places or direct contact with the relevant groups of people with the disease, may be induced by this disease. Inflammation of the respiratory mucosa occurs, and the submucosal capillaries are prone to rupture and bleed, leading to hemoptysis and other symptoms. If the condition persists in the child, parents are advised to take the child to the hospital for examination and treatment.